Walker D F
Mod Vet Pract. 1984 Apr;65(4):252-6.
A cow in full standing estrus is required to assess a bull's ability to copulate. Insufficient libido is not involved if the bull sniffs the cow's vulva and attempts to mount. Blood or pus exiting the penis or prepuce indicates penile or preputial lacerations or other lesions. Rear foot or stifle lesions, seminal vesiculitis, traumatic reticulitis or lumbar spinal injuries may prevent the bull from mounting. Preputial stenosis, penile adhesions, desensitization, hematomas or deviations, peripreputial abscess, cavernosal shunts, insufficient penile length and occlusions of the cavernosal canals may prevent intromission after mounting.
需要一头处于完全站立发情期的母牛来评估公牛的交配能力。如果公牛嗅母牛的外阴并试图爬跨，则不涉及性欲不足的问题。阴茎或包皮有血液或脓液流出表明存在阴茎或包皮撕裂伤或其他病变。后肢或膝关节损伤、精囊炎、创伤性网胃炎或腰椎损伤可能会阻止公牛爬跨。包皮狭窄、阴茎粘连、感觉迟钝、血肿或弯曲、包皮周围脓肿、海绵体分流、阴茎长度不足以及海绵体管道阻塞可能会阻止公牛爬跨后插入。
